KeySchemaElement.hs

{-# LANGUAGE DeriveGeneric #-}
{-# LANGUAGE DuplicateRecordFields #-}
{-# LANGUAGE NamedFieldPuns #-}
{-# LANGUAGE OverloadedStrings #-}
{-# LANGUAGE RecordWildCards #-}
{-# LANGUAGE StrictData #-}
{-# LANGUAGE NoImplicitPrelude #-}
{-# OPTIONS_GHC -fno-warn-unused-imports #-}
{-# OPTIONS_GHC -fno-warn-unused-matches #-}

-- Derived from AWS service descriptions, licensed under Apache 2.0.

-- |
-- Module      : Amazonka.DynamoDB.Types.KeySchemaElement
-- Copyright   : (c) 2013-2023 Brendan Hay
-- License     : Mozilla Public License, v. 2.0.
-- Maintainer  : Brendan Hay
-- Stability   : auto-generated
-- Portability : non-portable (GHC extensions)
module Amazonka.DynamoDB.Types.KeySchemaElement where

import qualified Amazonka.Core as Core
import qualified Amazonka.Core.Lens.Internal as Lens
import qualified Amazonka.Data as Data
import Amazonka.DynamoDB.Types.AttributeValue
import Amazonka.DynamoDB.Types.KeyType
import Amazonka.DynamoDB.Types.WriteRequest
import qualified Amazonka.Prelude as Prelude

-- | Represents /a single element/ of a key schema. A key schema specifies
-- the attributes that make up the primary key of a table, or the key
-- attributes of an index.
--
-- A @KeySchemaElement@ represents exactly one attribute of the primary
-- key. For example, a simple primary key would be represented by one
-- @KeySchemaElement@ (for the partition key). A composite primary key
-- would require one @KeySchemaElement@ for the partition key, and another
-- @KeySchemaElement@ for the sort key.
--
-- A @KeySchemaElement@ must be a scalar, top-level attribute (not a nested
-- attribute). The data type must be one of String, Number, or Binary. The
-- attribute cannot be nested within a List or a Map.
--
-- /See:/ 'newKeySchemaElement' smart constructor.
data KeySchemaElement = KeySchemaElement'
  { -- | The name of a key attribute.
    attributeName :: Prelude.Text,
    -- | The role that this key attribute will assume:
    --
    -- -   @HASH@ - partition key
    --
    -- -   @RANGE@ - sort key
    --
    -- The partition key of an item is also known as its /hash attribute/. The
    -- term \"hash attribute\" derives from DynamoDB\'s usage of an internal
    -- hash function to evenly distribute data items across partitions, based
    -- on their partition key values.
    --
    -- The sort key of an item is also known as its /range attribute/. The term
    -- \"range attribute\" derives from the way DynamoDB stores items with the
    -- same partition key physically close together, in sorted order by the
    -- sort key value.
    keyType :: KeyType
  }
  deriving (Prelude.Eq, Prelude.Read, Prelude.Show, Prelude.Generic)

-- |
-- Create a value of 'KeySchemaElement' with all optional fields omitted.
--
-- Use <https://hackage.haskell.org/package/generic-lens generic-lens> or <https://hackage.haskell.org/package/optics optics> to modify other optional fields.
--
-- The following record fields are available, with the corresponding lenses provided
-- for backwards compatibility:
--
-- 'attributeName', 'keySchemaElement_attributeName' - The name of a key attribute.
--
-- 'keyType', 'keySchemaElement_keyType' - The role that this key attribute will assume:
--
-- -   @HASH@ - partition key
--
-- -   @RANGE@ - sort key
--
-- The partition key of an item is also known as its /hash attribute/. The
-- term \"hash attribute\" derives from DynamoDB\'s usage of an internal
-- hash function to evenly distribute data items across partitions, based
-- on their partition key values.
--
-- The sort key of an item is also known as its /range attribute/. The term
-- \"range attribute\" derives from the way DynamoDB stores items with the
-- same partition key physically close together, in sorted order by the
-- sort key value.
newKeySchemaElement ::
  -- | 'attributeName'
  Prelude.Text ->
  -- | 'keyType'
  KeyType ->
  KeySchemaElement
newKeySchemaElement pAttributeName_ pKeyType_ =
  KeySchemaElement'
    { attributeName = pAttributeName_,
      keyType = pKeyType_
    }

-- | The name of a key attribute.
keySchemaElement_attributeName :: Lens.Lens' KeySchemaElement Prelude.Text
keySchemaElement_attributeName = Lens.lens (\KeySchemaElement' {attributeName} -> attributeName) (\s@KeySchemaElement' {} a -> s {attributeName = a} :: KeySchemaElement)

-- | The role that this key attribute will assume:
--
-- -   @HASH@ - partition key
--
-- -   @RANGE@ - sort key
--
-- The partition key of an item is also known as its /hash attribute/. The
-- term \"hash attribute\" derives from DynamoDB\'s usage of an internal
-- hash function to evenly distribute data items across partitions, based
-- on their partition key values.
--
-- The sort key of an item is also known as its /range attribute/. The term
-- \"range attribute\" derives from the way DynamoDB stores items with the
-- same partition key physically close together, in sorted order by the
-- sort key value.
keySchemaElement_keyType :: Lens.Lens' KeySchemaElement KeyType
keySchemaElement_keyType = Lens.lens (\KeySchemaElement' {keyType} -> keyType) (\s@KeySchemaElement' {} a -> s {keyType = a} :: KeySchemaElement)

instance Data.FromJSON KeySchemaElement where
  parseJSON =
    Data.withObject
      "KeySchemaElement"
      ( \x ->
          KeySchemaElement'
            Prelude.<$> (x Data..: "AttributeName")
            Prelude.<*> (x Data..: "KeyType")
      )

instance Prelude.Hashable KeySchemaElement where
  hashWithSalt _salt KeySchemaElement' {..} =
    _salt
      `Prelude.hashWithSalt` attributeName
      `Prelude.hashWithSalt` keyType

instance Prelude.NFData KeySchemaElement where
  rnf KeySchemaElement' {..} =
    Prelude.rnf attributeName
      `Prelude.seq` Prelude.rnf keyType

instance Data.ToJSON KeySchemaElement where
  toJSON KeySchemaElement' {..} =
    Data.object
      ( Prelude.catMaybes
          [ Prelude.Just
              ("AttributeName" Data..= attributeName),
            Prelude.Just ("KeyType" Data..= keyType)
          ]
      )